Thursday, March 23, 2017

Polecat X – P30 Build Report

This is my second P30 rubber free flight model, the first being the NJAPF design by Al Lidberg. My first P30 sat in my basement a long time before test flights and then last year I installed the DT system and flew it in contests.  For my skill level it did well and at the last contest I thought I might never see it again because it was circling ever higher far downwind.  It did come down and Gary Oakins found it, but with a stab DT I worry if another time it might be miles away. 

Polecat X P30

NJAPF First P30

Don DeLoach was running a special if you ordered multiple plans there was a discount so I ordered the Pearl e202 E36 and Polecat X plans with short kits.  I flew the Pearl E36 a good deal last year and learned much about e36, this year I wanted to get the Polecat X flying.  There was so much different about the constructions of the Polecat X than the NJAPF so I asked a lot of questions online. First I had to order carbon strips that reinforce the wing, ¼ mil Mylar covering, and picked up Balsarite at local hobby shop to stick the Mylar down. Wing and stab construction went well but then I built my first round tube fuselage by wrapping balsa around a pipe, that went alright too. Covering with the Mylar went better than I thought it might, some Design Master spray paint gives it some color. 

Wing Before Carbon Strips

Stab With Carbon Strips

As I completed each major structure I weighed it and then again after covering to compare with the suggested weights on the plan, my weights were close but slightly higher. This is really a detailed plan which I appreciate; no other instructions are really needed.  The contest wins for this model are really impressive and it is a plane that has been refined over many years of contest flying. With the rearhook is in the very back of the fuselage and with a light airframe a really long rubber motor can be used to get a slower climbing motor run that lasts a long time.  It is my understanding it could be possible to get a 2 minute max with the rubber still turning the propeller.

DT Only might not be available
Another new item I wanted to try was the BSD Micro electronic “DT Only”. The weight without battery should only be around 1.5 grams, the battery is a single cell lipo as small as 35 mah.  After trying some ideas of mine that did not work for the DT parts on the plane, I used the method shown on the plan when using a viscous DT timer.  The tiny servo built into the electronic unit does not have a lot of force so having the proper linkage is essential. Adjustment for DT time is done with a really tiny potentiometer that is rather fragile.  When you have it set correctly the DT time should be completely consistent in all conditions. This is the first time I am using the pop off wing idea in the DT which is said to be the only sure way to bring a P30 down from a strong thermal. 

Gizmo Geezer on Test Stand

Again I am using the Gizmo Geezer propeller system, I had installed this on my NJAPF p30 the end of last season and it worked well. With the Gizmo Geezer a certain amount of tension is held in the rubber so braiding is not needed and it has a good working freewheeling system. A couple of people had a concern with all the downthrust called for on the plan if the rear of the Gizmo Geezer might touch the top of the fuselage, I still need to test this.

Now if the weather would cooperate, I could try some test flights.

Update 3/29/2017 - I tried test flights on 150 turns, flies well.

Polecat X 150 hand winds

Bill Kuhl

Related Links  Pearl Free Flight website
Gizmo Geezer Propellers  DT Only timer does not appear to be on the website any longer.  Gizmo Geezer Review Part #1  Flying With the Gizmo Geezer

Tuesday, March 21, 2017

Radio Control Years – Tales of an Ancient Modeler

As promised I am continuing my book report of the Norm Rosenstock autobiography when Norm starts flying radio control. In this time period the modeler pretty much built most of the radio equipment themselves. Both transmitter and receiver were vacuum tube technology which required lots of batteries to supply the vacuum tubes which employed a heating element inside. The equipment was not proportional, that is a control surface moved when a button was pushed but even more difficult was to turn opposite direction two button pushes were needed and you had to remember what control you gave last.  Power to move the control surface was twisted rubber driving an “escapement”. Only one plane at a time could fly because the radio equipment was not very selective.

Good Brothers Guff at AMA Museum

Guff Radio

Another AMA Museum Plane
Museum Radios

I have never flown an escapement single channel airplane but have flown a couple types of single channel systems, one was pulse proportional and the other was a fairly modern toy-type airplane, Micro Flyer that used two push buttons for rudder and speed control by push buttons. Pulse proportional did move in sync with the control stick but the actuator connected to the rudder was continuously moving from one direction to the other. Control was done by moving more in a direction while pulsing back and forth.  It is amazing how well you can fly with rudder only control with some practice and proper airplane trim.  With the Mattel pulse proportional radio I flew a Littliest Stick powered by a Cox .020 and even did loops.

My Mattel Pulse Proportional Radio

My first equipment was “reeds” equipment which is mentioned in the book.  Reeds equipment was not proportional and you could only give one command at a time but multiple control functions were available. The equipment was obsolete at the time but I was happy to start flying RC at 13 years old, not too long after that I had a World Engines Blue Max proportional radio. I did have one plane flyaway with the reeds equipment but it was found by a farmer who returned it, I have another blog post telling the story.

My Reeds System Transmitter

Reeds Receiver

Reeds Receiver

People are so spoiled today with the modern radio equipment that comes ready to use and so reliable. There can be something to be said for being forced to innovate. Norm found solutions for smaller transmitter antenna, not needing all the expensive batteries in the transmitter; he built his own receivers, and had very stable airplanes that flew with only rudder control.  The only thing I can relate to this was when my flying buddies and I first started flying electric RC indoors; the equipment was so basic at first but advanced amazingly fast.  This spirit of innovation is what has really made this country great but we tend to not appreciate all the advances sometimes. My father was pioneering in the design of farm machinery in the same time period that advances were being made in radio control.  

My First Proportional Radio

In one of the chapters in the book, Norm teams up with Bill Winter, everyone has heard of Bill no doubt; they are trying to set a RC duration record.  The airplane which is basically a free flight with rudder control powered with .09 diesel. As it is using an escapement powered by twisted rubber they want to use as few turns of the rubber as possible by using the rudder control as little as possible. So using multiple transmitters they fly upwind with first transmitter and pilot upwind takes control as the other transmitter is shut off, actually they were going to try with three transmitters. The furthest upwind pilot puts the plane in a gentle turn so it can circle downwind in free flight mode until it is over the downwind pilot, the process was repeated.

Details About the book: Tales of an Ancient Modeler
Paperback: 179 pages Publisher: N. Rosenstock; First edition (August 25, 1989)
Language: English ISBN-10: 093457510X ISBN-13: 978-0934575102

National Model Airplane Museum - Muncie Indiana

From the AMA Model Aviation Hall of Fame Check Out these Biographies Mentioned in the Book  Norman Rosenstock    Joe Raspante  Larry Davidson  Bill Winter

Related Video  Good Brothers Pioneers in Radio Controlled Model Aviation 
Very interesting video from the AMA  Flying Single Channel Escapement RC  Flying Single Channel with a superregen rx and escapement My Video Clip about the Micro Flyer

Related Blog Articles 
First part of the book about free flight. 

Bill Kuhl

Tuesday, March 14, 2017

Norm Rosenstock – Tales of an Ancient Modeler

History is more interesting to me as I get older; studying it I believe gives one a better appreciation of what others have contributed in the past and a better understanding of what the future could hold. For a few years I was creating documentary videos of local history. One of the videos was about the local full-scale aviation hero Max Conrad. The interest in Max started after reading the Book into the Wind the biography of Max Conrad.

Another Interesting Book 

More recently I have been more active in outdoor free flight competition and was a contestant last summer in the Outdoor Free Flight Nationals in Muncie Indiana. Along with a huge number of types of free flight models were the old time models both rubber powered and gasoline engine powered. For the first time I did a tour of the National Model Aviation Museum on the site, it was the closest thing to time travelling to be able to see the many older and famous models.

National Model Aviation Museum Muncie Indiana
Norm was cutting parts for this kit at one of his jobs

Carl Goldberg Valkyrie in Museum 
1950's Hobby Shop Recreated at Museum

After losing my first Tales of an Ancient Modeler book I recently ordered a used one in good shape for a reasonable price. Norman Rosenstock begins his modeling story in 1932 when he built his first model airplane at the age of eight, probably about when I started also. When Norm was 14 he got his first gas engine a Brown Jr. which cost $10, a lot of money during the Depression. To fly the large gas engine powered free flight models he designed and built, Norman and his friends would make the one hour subway ride to Van Courtland Park in the Bronx New York.  It was interesting to me that another famous modeler Frank Zaic was also riding the subway to Van Courtland Park to fly a few years earlier. 

Oldtimer Flying Muncie 2016

What I take away from reading this book is the hardship the young people of this time period endured to fly the model airplanes they built with inferior materials and tools. Norm tells of an incident where he wanted a new engine really bad and skipped lunch for weeks to pay it off. Before 1941 free flight models did not have dethermalizers to bring the plane down, so no doubt many models were lost.  It is interesting also how many famous modelers did come from the New York area such as Sal Taibi,  Joe Raspante, Larry Davidson, and more.  Larry has emailed me about his friendship with Norm.

Larry Davidson photo Lanzo Bomber

Larry Davidson photo Brown engine

I am going to end this blog report with a bunch of sources to check out further and a list of vendors selling materials related to older model aircraft. In the second half of the book Norm describes his adventures into radio control models, I will write another blog post on that. Some of the video links are of 1930’s subways, ignition model engines running, and old model planes flying but not in New York. Another book that relates to the history of model aviation is Do You Speak Model Airplane by Dave Thornburg, I plan to read that book again

Bill Kuhl

Update Norm is mentioned in this article on the Mite 098 Diesel.  

Tales of an Ancient Modeler by Norman Rosenstock 
Paperback: 179 pages Publisher: N. Rosenstock; First edition (August 25, 1989)
Language: English ISBN-10: 093457510X ISBN-13: 978-0934575102

Do You Speak Model Airplane  by Dave Thornburg
Publisher: Pony X Press (January 1, 1992)  ASIN: B002ANRY8G

Phd Dissertation on Model Aviation in the past almost 400 pages

Really interesting reading from AMA website
AMA Model Aviation Hall of Fame “Established in 1969, the Hall of Fame honors men and women who have made significant contributions to the sport of aeromodeling. Contributions may be in volunteer or administrative activities, product development, competition performance, or a variety or combination of activities.”

National Model Aviation Museum

Ask Claire from Nation Model Aviation Museum – I have been watching the live broadcasts through Facebook

Vendors of Related to Older Free Flight Model Airplanes
Larry Davidson - - ignition engine parts
Texas Timers – – timers for ignition engines
Jim O’Reilly Plans -  plans and short kits
BMJR Models -   kits  Old Time Rubber models and propellers   plans  kits  Bob Holman Plans and short kits  Free Flight Supplies Mike Woodhouse UK  plans National Free Flight Society  Balloon Wheels
Aero Dyne  - plan website is in process of being transferred. Outerzone free plans to download
 Hip Pocket Aeronautics Builder’s Plan Gallery free plans to download must be a member 
SAM - The Society of Antique Modelers   find additional vendors on the website and a wealth of information.  

Just Added - Belair Vintage Kits  Norm Rosenstock appears in group photo.

Video Links   Borough Hall subway in the 1930s - Brooklyn, New York   Mighty Atom model airplane engine 1934   Pioneers of Model Aviation - Carl Goldberg   Newsreel of 1936 Model Airplanes Championship, Brown Jr. Engine    Brown Jr airplane engine running  1939 model flying Dublin Ireland

Tuesday, March 7, 2017

Bad Axe Embryo – Thermals Do Not Care

I am less than pleased with myself in the construction and covering job on the Bad Axe embryo class rubber free flight from Volare Products. In no way can I blame the short kit or the plans, some of the problems I believe is in wood I selected for stringers in constructing this model. The Bad Axe embryo won the Embryo Event at the 2016 Outdoor Nationals Free Flight Contest in Muncie Indiana for George Bredehoft.  I was at that contest and met George in person for the first time. I took a picture of his Bad Axe while he was winding but somehow missed the flight. 

Bad Axe Embryo

Thermals do not care what an airplane looks like is what a couple of people told me when I mentioned my less than stellar covering job. Now I have built small rubber models before and did a pretty good job including two embryo models, the Peck Prairie Bird and the Volare Sky Rocket and the covering went on fairly well. These were full kits that included all wood. Another similar sized model I built was a Herr Champ that unfortunately included stringer wood that was too heavy, the covering went on fine but the model barely flew.

Picture Does Not Really Show Bad Fuselage

When I thought about building the Bad Axe I wanted to keep it light so I ordered some really light 1/16” square stock. When I built the fuselage the outside stringers just did not bend evenly and by the time it was constructed it had this wavy look to it if you looked closely down the sides. Various times the stringers would break on me so I doubled the 1/16” stringers in the front of the fuselage.  In doing some research I found some other people had trouble with the pre-cut 1/16” balsa. Bob Clements gave me a suggestion of a business that sold some good pre-cut balsa,  Hobby Specialties I will have to check them out in the future.

George's Nats Winning Bad Axe

Covering the Bad Axe I started with the tail surfaces, I was afraid the stabilizer would warp so I covered that rather loose and kept it pinned down while spraying on clear Krylon.  To adhere the tissue I used the UHU gluestick for the first time which many modelers use. It is not available locally so I ordered it through Amazon and it took a month to come from Thailand. Then I found out George sells it through Volare. This gluestick seemed to apply smoother than some other brands I have tried. The wing I did water shrink but pinned it down. It came out fairly well using some heat while shrinking.  I tried mixing rubbing alcohol with water for the shrinking  which should slow down the shrinking process. The fuselage I could not really get in a jig and this gave me fits, several places I cut out sections of tissue where it wrinkled and tried again but still not much better.

Could not get Wrinkles Out

Even though the fuselage has some uneven bends in it I think it ends up fairly straight back at the tail surfaces.  I added a fuse DT system with the front of the wing raising up. On my Guillow’s Lancer I had this type of DT and it appears to work pretty well. 

It has been extremely windy recently but I hope to get a chance to fly the Bad Axe on the first calm day. Included below is an extensive listing of resources including articles on covering with tissue.

Update 3-9-2017

I made some short test flights with less than 100 turns, flight pattern appears to be fairly close.

Bill Kuhl

Vendor Links                      Bad Axe Embryo on Volare website   About George Bredehoft designer Volare Products  UHU Gluestick   Hobby Specialties

Articles on Covering with Tissue

Related Blog Articles

Thursday, February 23, 2017

Finishing Up the 2017 Fleet of Free Flight Models

I have been really busy building free flight models over the winter; contest flying at the 2016 Nats and two Minnesota contests has really got me excited about free flight.  Two of the models I had finished up the end of 2016 and made some test flights; BMJR Sky Demon e20 and Retro RC Retro Gnome Hi-start glider. Last weekend it was warm giving me a chance to further test fly those airplanes.  

BMJR Sky Demon

With the e20 Sky Demon I had straightened out a warp in the wing and gave it more downthrust. The power portion of the flight looked good but it was stalling in the glide. I put a tiny shim under the trailing edge and the flight looked much better. For my first attempt at towing up the Retro Gnome I had a friend launch it and I ran with some of the string. It went up but as I looked back I was blinded by the sun so did not see the rest of the flight.  My friend said it stalled; the towline was still attached by the auto rudder pin.  There was some damage to the wing but I tried it with the hi-start and a small amount of stretch. The glider went up fairly straight but the pin did not want to come out, after a few tries I gave up.

Retro Gnome Good Flight
Leading Edge Damage

That evening I repaired the glider and tried to stretch the rudder line and added a weight to the towline. The next morning before the wind came up I tried again.  After several attempts I was still having trouble with the line not releasing at the pin. On one flight it did release and the glide looked really good, just before it landed the DT went off bringing it quickly down. I have since redone the auto rudder line with less tension and using a washer that slips over a pin.


Polecat X P30
Starduster E36

Jetstream Towline

I have four more planes that are almost done but I am finishing up final details, mainly rigging the DT; Wilbur old time rubber model, Starduster e36 electric, Polecat X P30, and Jetstream towline model. I learned a lot building those models and I asked a lot of questions. I am going to Thank the people I remember giving me suggestions, no doubt I missed some people.  In no particular order:  Bob Hanford, Dan Berry, Jack Murphy, Hank Sperzel, Hank Nystrom, Dohrm Crawford, Rudy Kluiber, Norm Furutani, Ronnie Espolt, Paul Bradley, Brian Malin, Jim O’Reilly, Don DeLoach, Larry Davidson, Lee Campbell, Mike Myers, Steve Pollina, George Bredehoft, Gary Hinze, Harry Grogan, Chuck Powell, John Barker, Manuel Cisneros, Simon Blake, and Denny Dock. Also a list of the vendors that I used.

Bill Kuhl

Larry Davidson -  - parts
Texas Timers –   mechanical & electronic timers
BMJR Models -   Sky Demon Starduster e36
PearlFreeFlight -   Polecat X
Jim O’Reilly Plans -  Jetstream & Wilbur
Volare Products -  Propeller
FAI Model Supply -
Starlink Flitech -   Bandburner timers
BSD Micro -  elecronic timers
Everything Hobby –  local hobby shop
Retro RC -  Retro Gnome

Related Articles

 Wilbur -

Retro Gnome -

Starduster e36 -

Sky Demon e20 -

Friday, February 10, 2017

Cost Versus Benefits - My New Prius

When I purchased my first Prius in 2012 I was rather apprehensive if it was the right decision, depending on so much electronics technology to keep the car functioning was somewhat scary. People that have never owned a Prius may bash it but the people that have them seem to think it is one of the best vehicles they have ever owned. In the past I had driven mainly American vehicles but the first new vehicle I had purchased, an American minivan turned out to be a huge disappointment. Now you are not going to pull a horse trailer with a Prius or jump start your neighbors car but I think the positives outweigh the negatives.

2017 Prius

After driving the Prius for 5 years and 46,000 miles with no problems I was extremely pleased. The gas mileage varied with 53.5 mpg average being the best it did by the end of one summer, winter mileage is still good but down several mpg from summer. I did all the suggested maintenance but did not have a single issue with the car. Failure of the hybrid batteries was a concern although there is a really long warranty. I had been told that the trade-in value of my Prius would be good, so when the new generation Prius came out, I thought after it had been out a year I would look into trading mine for the new technology.

Better Visibility Out Side Window

Now there are people that really do not like the looks of the new Prius, or previous versions either. The new body style has a slightly lower coefficient of drag than the previous generation which was already low.   The new version has been improved in many ways such as the rear suspension, even better gas mileage, more power, more comfortable seats, more cargo room, and lots of electronic wizardry. It has radar cruise control to keep an even gap with the car ahead and another feature to turn it back if it should start driving off the edge of the road. The Bluetooth interface connects to a smartphone so it can even read an incoming email to you in a female voice. More usable to me is how it connects with Google Maps.

New Dash Better in Bright Sun

Two tiny objections I had with my previous Prius I think have been remedied. The new color dash screen appears easily visible in bright sunlight. Vision out the rear of the car appears to be better also and it came with a backup camera standard. Even in my short test drive with my salesperson from Dahl Toyota, Ken Koeller I could tell the ride and handling in the new model was better.

If pressed for the biggest reason I wanted to purchase a Prius I would have to say I like things that are efficient. How a car can average 50 mpg and not be kiddie car size is through some very clever engineering. In previous blog posts on my 2011 Prius I explained some of the engineering.

I am so excited the number of views to this blog is less than a thousand away from the 200,000 view mark.

Bill Kuhl

Previous Prius Posts   - Dahl Toyota Winona

Friday, January 27, 2017

RC Flying from Snow and Water Parkzone Icon A5

As much as I do enjoy building model airplanes and flying the airplanes I build, I do have a rather large collection of Ready to Fly (RTF) foam airplanes. The radio system I use is a Spektrum DX 9 which is completely compatible with the receiver in these planes and with a model memory of over 200 models I should be good for a couple years at least. My two local hobby outlets stock some of these planes and I have always purchased them local.  These models are great to take to a park or schoolyard where I make sure I am never flying over anyone. 

Parkzone Icon A5

Assembled Model can be Stored in Original Box

In the stock of RTF models at my local hardware store I had noticed an amphibious model on the shelf for awhile; the Parkzone Icon A5. In my modeling bucket list, flying from water was something I wanted to try. When I went to the hardware store a few weeks ago to buy some music wire, I noticed many of the foam RTF planes were on sale, I decided now was the time to purchase the Icon A5. It was winter but I thought this plane should also be great for flying from the snow, and it is.

Flying from Snow
I Flew with Gloves on Sometimes

After rain over snow, the icy snow had little resistance and the Icon took off with a couple of feet.  It flies at a good speed but will slow down fairly slow to land, so much fun doing touch and go’s but what I had not noticed was the bottom of the plane was full of gouges in the snow. I filled in the largest gouge with foam held down with epoxy. Then I used clear tape over the bottom to protect it from further gouges (Thanks Dan B for the suggestion). 

Icy Snow was Tough on Foam Bottom

Last weekend it was above freezing and some rather large puddles were to be found many places, so I thought this would be a great opportunity to try flying from water. The water was really cold but it was only a couple of inches deep. On the first day of flying from water there was little wind to take off into and the plane took most of the length of the puddle to take off. Landing in the water went well but the plane sure slowed down in a hurry. Steering on the water worked well. On the next day I took off into some wind and the plane appeared to take off a little quicker. Some of the time I flew with bare hands and some of the time I wore gloves. I have purchased a transmitter mitt which should arrive soon, that way my bare fingers will be on the sticks and hopefully warm. Actually looking forward to flying from a lake when the water is warm enough to walk into.

No Outrigger Pontoons

Really Wet Snow Sticking to Bottom

The full scale Icon A5 is really an interesting airplane with features such as wings that fold back and several available safety features such as a whole airplane parachute and stall resistance features. Naturally the price is rather high coming close to $200,000. There is also another larger RC foam model of the Icon A5 available; my understanding this is a new version of the one that had been discontinued.

Bill Kuhl

Update 1/29/2017 Transmitter Mitt

I tried the transmitter mitt I just received and it appears to keep my hands warm. Trouble was it was really windy and the plane hit the ground knocking the stab off. It had come off one time before so this time I epoxied it back on.